I'm trying to book a flight on SQ in J from BNE-NRT however for some reason my preferred return flights (SQ11 connecting in SIN to SQ245) doesn't come up as an option on my travel date despite both being able to be booked individually. Does anyone have any idea as to why this might be and any solution to the problem? Will booking it as a multi-trip calculate it as the same price? If I do this are there any issues with having my baggage checked all the way through on both legs?